Method of making alloys



Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE WHEELER P. DAVEY, OFSTATE COLLEGE, PENNSYLVANIA, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK METHOD OF MAKING- ALLOYS No Drawing.

This invention relates to a new and improved method of making alloys.

An object of this invention is to provide a method whereby asubstantially homogeneous alloy is produced.

Another object of the invention is to pro duce an alloy without fusingthe metals which comprise the alloy.

Ordinarily an alloy may be made by fusing the metals which make up thealloy.

owever, in carrying out the ordinary processes in which fusion of themetals is employed, though it is desirable, it is often diflicult toobtain an alloy in which there is a substantially homogeneousdistribution of the metals. In order to obtain such a product it isnecessary to have the components of the alloy intimately mixed together.

I have discovered a method whereby I can produce alloys which have amore homogeneous distribution of the elements than usually follows fromthe ordinary processes which use fusion. Briefly, my process consists oftwo main steps: first, the preparation of an exceedingly intimatemixture of easily reducible compounds, such as the oxides or hydroxidesof the metals; and second, the reduction of this mixture to the metallicstate. The essential point in this process is to start with a solutionof a mixture of mutually nonreactive compounds which contain theelements desired in 'the final alloy, since the molecules in solutionare intimately in contact with each other, so that a final product maybe obtained which will be as homogeneous as possible.

In carrying out my invention I first start with solutions of compoundsof the metals I desire in the finished alloy. I select the proportionsof the compounds in such manner that I will have the desired proportionsof metal in the finished product. Such compounds are selected which arewater soluble and which when 'in solution will not interact. Forexample, I may make a solution of the nitrates of each of the metals Idesire in the alloy. A convenient, desirable, and preferred way toproduce the oxides or hydroxides of the metals in the form of a veryintimate mixture is to squirt the solution of Applicationfiled May 28,1929. Serial No. 366,768.

the compounds of the metals in the form of a fine, high velocity streaminto an excess of alkaline solution such as an aqueous solution ofammonium hydroxide or sodium hydroxide. Under such conditions ofprecipitation, the mixture of the oxides or hydroxides will beexceedingly intimate though non-colloidal. Such mixture will be muchmore intimate than it is possible to obtain by mechanically mixing theoxides or hydroxides in the solid state. Also the oxides or hydroxidesof each of the metals will all be precipitated completely and togethersince there is always present under these conditions an excess ofhydroxide and as each particle of metal strikes the solution it isimmediately in contact with sufiicient hydroxide to insure complete andintimate precipitation. The precipitate thus obtained is separated andis reduced in an atmosphere of hydrogen ata suitable temperature, thusgiving a powder of a metallic alloy in which the components are veryintimately mixed. During reduction the metals come out of the moleculesof oxides or hydroxides with the minimum chance for migration throughoutthe mass and therefore with an optimum chance of having a homogeneousdistribution of the metals in the alloy. The powder of metallic alloymay be pressed up and sintered and the sintered material may besubsequently subjected to mechanical working.

I have prepared by means of this process brass without fusion, and alsoalloys of nickel and iron, two metals which difi'use very slowly in thesolid state to produce'equilibrium. My invention, however, is notlimited to the production of these alloys, but is applicable to thepreparation of other alloys as well as those indicated. It will beobvious from the disclosure of the invention given in the foregoingspecification that the process is limited to the precipitation of metalsfrom solution in which the metal is a positixe ion. that is, a metalwhich is normally base forming.

WVhat I claim as new and desire to secure by Letters Patent of theUnited States, is,-

1. The method of making an alloy from normally base forming metals whichconsists in converting a mixture of mutually non-reprecipitate andreducing it to the metallic active solutions of compounds of the metalsstate in a stream of hydrogen at a. suitable desired in the alloy to anintimate physical temperature, and finally pressing andsinternon-colloidal mixture of mutually non-reacing the finishedproduct. 5 tive compounds which are reducible, and then In Witnesswhereof, I have hereunto set 70 reducing said mixture to the metallicstate. my hand this 24th day of May, 1929.

2. The method of making an alloy from WHEELER P. DAVEY. normally baseforming metals which consists I in preparing non-reactive solutions ofcompounds of the metals desired in the alloy, 75

obtaining therefrom an intimate physical non-colloidal mixture of theoxides or hydroxides of the metals, and then reducing this mixture tothe metallic state. 3. The method of making an alloy from V. V 90normally base forming metals which consists in preparing non-reactivesolutions of compounds of the metals desired in the alloy, soprecipitating the oxides or hydroxides of the metals with an alkalinesolution that an intimate physical non-colloidal mixture is obtained,and reducing the precipitate in a stream of hydrogen at a suitabletemperature. 25 4. The method of making an alloy which consists inpreparing a solution of a mixture of compounds of the metals desired inthe alloy which compounds do not react in solution, the compounds beingsuch that the 30 metals desired in the alloy form positive ions when thecompound is in solution introducing this solution so prepared in theform of a fine high velocity stream into an excess of an alkalinesolution to obtain an intimate 35 physical non-colloidal mixture of theoxides or hydroxides of the metals, and then reducing the mixture inhydrogen.

5. The method of making an alloy which consists in preparing a solutionof mutually non-reactive compounds of the metals de- 7 sired in thealloy in proportions such that the elements will be present in theproportions desired in the finished product, the compounds being suchthat the metals .de- 45 sired in the.alloy form positive ions when thecompound is in solution introducing the solution prepared in the form ofa fine high velocity stream into an excess of alkaline solution toobtain an intimate physical non- 50 colloidal mixture of the oxides orhydroxides of the metals, separating the precipitate and reducing to themetallic state in a stream of hydrogen at a suitable temperature, andfinally pressing and sintering the finished 55 product.

6. The method of making a brass which onsists in preparing a solution ofthe nit ates of the metals desired in the brass in proportions such thatthe metals will be pres- 60 ent in the proportions desired in thefinished product, introducing this solution in the form a of a fine highvelocity stream into an excess of alkaline solution to obtain anintimate a physical non-colloidal mixture of the oxides or hydroxides ofthe metals, separating the

